Method and apparatus for biodegradation of alkyl ethers and tertiary butyl alcohol

ABSTRACT

Disclosed is a method for treating groundwater, or other water streams contaminated with oxygenate(s), particularly MTBE and TBA, characterized by improved biodegradation of MTBE, the biodegradation of TBA, and reduced frequency of the need to change the carbon bed, which comprises inoculating a biodegrader capable of degrading said oxygenate on an activated carbon bed through a rigid tubular instrument having a plurality of holes around the circumference of the end used for inoculation of the carbon bed by a method that optimizes dispersion and colonization; and flowing said groundwater, or other water stream contaminated with said oxygenate through a structure having a top, bottom and sides and a predetermined volume containing said bed of activated carbon having said biodegrader inoculated thereon. The invention is also an apparatus for biodegradation of oxygenate(s).

FIELD OF THE INVENTION

This invention relates to the purification of groundwater contaminatedwith oxygenate(s) such as alkyl ethers and tertiary butyl alcohol. Thisinvention further relates to a method and apparatus that result in theefficient biodegradation of these compounds to carbon dioxide and water.In particular, the invention relates to the remediation of groundwatercontaminated with methyl-t-butyl ether (MTBE) and other ethers usingfixed beds of granular activated carbon (GAC) seeded with specific MTBEdegrading bacteria cultures and to a new method of seeding said carbonbeds to avoid plugging, where the required amount of culture to degradethe MTBE can be determined by a formula. Also disclosed are oxygen andnutrient delivery systems.

BACKGROUND OF THE INVENTION

In response to the 1990 Clean Air Act Amendments gasoline suppliersbegan to blend fuels with oxygenate(s), such as alkyl ethers,particularly methyl-t-butyl ether (MTBE). MTBE often constitutes as muchas 10 to 15% by volume of unleaded gasoline.

After using oxygenated fuels for about a decade, it has become apparentthat the cleaner burning fuels pose distinct threats to groundwaterresources. In particular, many oxygenate(s) are very soluble in waterand are slow to degrade in the environment; hence they tend toaccumulate in water resources once released into the environment.

Due to leaks in underground storage tanks or spills, the groundwater atmany gasoline retail, distribution, and manufacturing sites iscontaminated with benzene, toluene, ethyl benzene, and xylene (BTEX), aswell as MTBE and other ethers. For example, MTBE has been detected ingroundwater with high frequency in many states and there are welldocumented cases of impacts to municipal water supply wells. Due to thefact that MTBE and other ethers are characterized by the properties ofhigh solubility in water, relatively low volatility compared to BTEX,relatively low carbon sorption coefficient, and poor biodegradability,the ethers are more easily transported in groundwater aquifers than BTEXand do not degrade through natural attenuation. While MTBE can beremoved from recovered groundwater by treatment with granular activatedcarbon beds (GAC), it is relatively expensive compared to the treatmentof BTEX because the GAC beds are subject to frequent exhaustion. Equallyimportant, GAC is not effective at all on TBA that is found along withMTBE in contaminated groundwater.

Where groundwater contaminated with BTEX, MTBE, and other ethers istreated using activated carbon there is a need in the art for a methodwhich reduces the need for frequent changing of the carbon bed and whichalso addresses the problem of degrading tertiary butyl alcohol.

In situ methods for the removal of contaminants from ground water areknown. U.S. Pat. No. 5,277,518 discloses a method of in situ removal ofcontaminants from soil or from ground water, the method comprising thesteps of establishing in situ at least one venting well comprisinggas-permeable openings at an upper portion thereof and a condensatedrain at a lower end thereof and removing volatile contaminants in theground water or soil through the venting well. This referencecontemplates injecting microorganisms, nutrients for the microorganisms,and oxygen. U.S. Pat. No. 5,472,294, to the same assignee, and U.S. Pat.No. 5,653,288, to the inventors of '518 and '294, provide improvements,including providing an oxygen-containing substance to the contaminantsand enhancing lateral dispersion of injected materials.

U.S. Pat. No. 5,037,240 discloses a method of ‘in situ’ collection andtreatment of floating, sinking and dissolved contaminants in a soilenvironment which involves installation of wick-like drains in at leasta portion of the waste site on the down-gradient side of in-ground waterflow. Some of the wick drains include porous or slotted pipes and areemployed for the injection of treating chemicals or reagents into thecontaminated soil for treatment in place prior to normal flow into theaquifer. Some of the drains may be employed for injection of bacteria ormicrobes, nutrients and/or air. U.S. Pat. No. 5,054,961, to the sameassignee, discloses the added feature of forming an in-grounddiversionary water barrier as a boom around at least the downstream areaof said soil environment. These in situ methods do not discuss the useof carbon beds. U.S. Pat. No. 5,425,598 discloses an apparatus andmethod for sparging ground water by developing density driven convectionand promoting the physical removal and biodegradation of contaminants.

In “Performance of Fixed Bed Reactors with Two-Phase Upflow andDownflow”, Iliuta, Ion, J. Chem. Tech. Biotechnol. 1997, 68, 47-56, theperformance of two-phase upflow and downflow fixed bed biofilm reactors,with the biocatalyst immobilized on the porous solid support wasexamined with the degradation of phenol selected as the test process.

Granular activated carbon (Hereafter GAC) has been used for treatment ofwater and wastewater at the surface. “Experiences with GAC-Fluid Bed forBioremediation of BTEX-Contaminated Groundwaters”, G. Mazewski, J.Tiffany & Hansen, Biotechnol. Ind. Waste Treat. Biorem., (Pub.1996)333-344(1992) relates information regarding a demonstration projectand a full scale remediation project to treat groundwater from anoperating recovery well at a bulk storage terminal using granularactivated carbons. In this work the removal of BTEX was moresatisfactory than the removal of other compounds such as MTBE.

In “Bioreactor Treatment of MTBE and TCE In Contaminated Ground Water”,by Miller, Michael E., et al, from In Situ and On-Site Bioremediation,Pap. Int. In Situ On-Site Biorem. Symp., 4^(th) (1997),,Vol. 5, 89-94,the authors discuss a study at the Sparks Solvent/Fuel Site (Sparks,Nev.) where ground water containing MTBE, BTEX and various chlorinatedsolvents is treated in two granular activated carbon-fluidized bedbioreactors operating in parallel. For the first few weeks after reactorstartup, 85% of the influent MTBE was removed, however effluent MTBEconcentrations soon increased, indicating that the initial removal waspredominately due to sorption and MTBE removal efficiencies dropped to10-15%. Later carbon containing unidentified MTBE-degrading cultures wasadded to one of the fluidized bed bioreactors and the efficiency in thatreactor increased to about 75%.

In “A Review of Potential Technologies for the Treatment of Methyltertiary Butyl Ether (MTBE) in Drinking Water”, discussing a study byAnthony Brown et al., University of Southern California Department ofCivil and Environmental Engineering of the Metropolitan Water Districtof Southern California, City of Santa Monica, the authors mention theuse of GAC, along with polymeric resins and chemically modified clays,but state at page 136 adsorbability is low on GAC, adsorption capacityfor MTBE is low, and frequent GAC regeneration is required.(API-National Ground Water Association “Petroleum Hydrocarbons andOrganic Chemicals in Ground Water: Prevention, Detection, andRemediation” Conference, Houston 11/12-14/1997)

The use of bacteria or naturally occurring microbes for biodegradationis known. U.S. Pat. No. 4,493,895 discloses microbial degradation ofhalogenated organic compounds. U.S. Pat. No. 5,641,679 disclosesbiodegradation of compounds such as naphthalene, haloaromatics, benzene,etc.

U.S. Pat. No. 5,474,934 discloses aerobic biodegradation of ethers usingAmycolata sp. or a mutant. U.S. Pat. No. 5,814,514 discloses the use ofpropane-oxidizing bacteria for degrading an alkyl ether.

K. Mo, et al. Appl. Microbiol. Biotechnol. (1997) 47:69-72 proposesisolating from activated sludge and fruit of the gingko tree three purecultures, belonging to the genuses Methylobacterium, Rhodococcus, andArthrobacter, that are capable of degrading MTBE.

A microbe which is said to digest MTBE is described in a newspaperarticle by Steve Hart in The Press Democrat, Santa Rosa, Calif., 1August (1999).

U.S. Pat. Nos. 5,750,364 and 5,902,734 to Salanitro, assigned to ShellOil Co., disclose mixed bacterial cultures capable of biodegrading MTBEand TBA to carbon dioxide and water. U.S. Pat. No. 5,811,010 toSalanitro, assigned to Shell, discloses aerobic degradation of t-butylalcohol using activated sludge. These three U.S. patents areincorporated herein by reference in the entirety.

It is apparent from the art that it is more difficult to degrade MTBEand other ethers than BTEX due to the properties of the ethers. Theethers have high solubility in water, relatively low volatility comparedto BTEX, relatively low carbon sorption coefficient, poorbiodegradability, and are more easily transported in groundwateraquifers than BTEX. MTBE can be removed from recovered groundwater bytreatment with a GAC bed, but due to the fact it is not very hydrophobicand the capacity for sorption is not as high as BTEX, it is relativelyexpensive to remove by this method compared to BTEX due to frequentexhaustion of the activated carbon beds. In addition, activated carbonis not effective at all on TBA which is often found along with MTBEcontaminated groundwater, and is even less hydrophobic.

There is a need in the art for a method of treating groundwatercontaminated with these more recalcitrant chemicals. In addition, wherean activated carbon is used to assist in degradation of MTBE, there is aneed for a method that reduces the need for frequent replacement of thecarbon beds. Furthermore, there is a need for a method that alsoprovides for the degradation of TBA.

SUMMARY OF THE INVENTION

In accordance with the foregoing the present invention provides a methodand apparatus for degrading oxygenate(s), including, but not limited to,ethers, alkyl ethers and alkyl alcohols, particularly branched alkylethers/alcohols, more particularly tertiary carbon atom-containing alkylethers/alcohols, and still more particularly MTBE and TBA, which reducesthe need for the frequent replacement of activated carbon beds and, atthe same time, allows for the removal of TBA where it would otherwisehave not occurred. The invention comprises:

a) Inoculating a biodegrader capable of degrading said oxygenate on anactivated carbon bed through a rigid tubular instrument having aplurality of holes around the circumference of the end used forinoculation of the carbon bed; and

b) Flowing said groundwater, or other water stream contaminated withsaid oxygenate(s) through a structure having a top, bottom, and sides,and a predetermined volume containing said bed of activated carbonhaving said biodegrader inoculated thereon.

Also within the scope of the invention is supplying oxygen in the formof hydrogen peroxide and other nutrients to said bacteria.

In determining the amount of said biodegrader required to degrade saidoxygenate(s) the following relationship is useful:$B = \frac{\left( {0.1 - 10} \right)\quad {\left( {C_{in} - C_{out}} \right) \cdot F}}{A}$

Where

B=dry mass of biomass degrader needed, (gm)

G_(in)=influent MTBE or other component influent, (mg/I)

C_(out)=desired effluent MTBE or other component, (mg/I)

F=flow rate of water to be treated, L/hr

A=degrader activity in mg of compound degraded/hr/gm of biomass

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of the GAC inoculation equipment and procedure.

FIG. 1A is an enlarged view showing the end of the inoculation wand.

FIG. 2A is a graph showing the influent and effluent levels of MTBE andthe performance of the BioGAC.

FIG. 2B is a graph showing the influent and effluent levels of TBA andthe performance of the BioGAC.

DETAILED DESCRIPTION OF THE INVENTION

The present invention (BioGAC) provides a method for the biodegradationof oxygenate(s) in, for example groundwater, by flowing contaminatedfluids through fixed beds of granulated carbon inoculated with aMTBE-degrading microorganism. This method provides improved breakdown ofMTBE, reduces the need for frequent replacement of activated carbonbeds, and, in addition, provides for the removal of TBA. In referencesknown in the art, where carbon beds alone are used, MTBE adsorption isexpensive and TBA is not adsorbed at all.

The present invention provides a method for remediating oxygenate(s).Oxygenate(s) is a substance added to a hydrocarbon to increase theamount of oxygen present. Oxygenate(s) as described in the presentinvention are oxygen-containing hydrocarbons which include, for example,but are not limited to, ethers, alkyl ethers and alkyl alcohols,particularly branched alkyl ethers/alcohols, and more particularlytertiary carbon atom-containing alkyl ethers/alcohols. Still moreparticularly MTBE and TBA contaminants in soil and groundwater aredegraded by flowing the contaminated material through a fixed bed ofgranulated carbon seeded with bacteria known to biodegrade saidoxygenate(s) to carbon dioxide and water. Examples of oxygenate(s)degraded with the present invention include, but are not limited to,diethyl ether (DEE), dimethyl ether (DME), methyl ethyl ether (MEE),methyl n-propyl ether (MPE), ethyl n-propyl ether, methyl isopropylether, ethyl isopropyl ether, di-t-butyl ether, di-isopropyl ether(DIPE), di-isobutyl ether, isopropyl isobutyl ether, ethyl t-butyl ether(ETBE), t-amyl ethyl ether, t-amyl propyl ether, t-amyl isobutyl etheror methyl-t-amyl ether.

A wide variety of reactors known in the art would be suitable for usewith BioGAC. Suitable reactors include column or drum, alone or in aseries. In Example 1, described herein, a 55-gallon carbon drum was usedto demonstrate the invention, however vessels containing 200 lbs. ofcarbon or more are within the scope of the invention. The reactor isfitted with piping to provide nutrients and an oxygen source. Thereactor is preferably also fitted with a gauge to monitor pressure andan air vent to relieve any build-up of process gases.

A wide range of granular activated carbon size particles are suitablefor use in the activated carbon bed of the BioGAC. Mesh size is notcritical, however it is believed that carbon particles smaller than 50mesh (U.S. Standard sieve) might not be as satisfactory, because a bedof such particles tends to plug with solids. Suitable granular activatedcarbons that are available commercially include, but are not limited to,Calgon Filtrasorb 600, Barnebey Sutcliffe Coconut Shell carbon, and USFWestates CC-602. A suitable granular activated carbon which was used todemonstrate the invention is USF Weststates CC-602 Carbon. This gradewas selected as best meeting the objective of minimum plugging.

Critical elements of the present invention include: 1) Biodegraderbacteria that have the ability to degrade oxygenate(s), including alkylethers and alkyl alcohols, particularly branched alkyl ethers/alcohols,and more particularly MTBE and TBA, down to carbon dioxide and water;and 2) The method of inoculating the GAC with the biodegrader in theoptimum manner to accomplish biodegradation and avoid plugging of theGAC, employing a specially designed rigid tubular instrument forinoculation. Also disclosed is a method of determining the amount ofbiodegrader needed by using the relationship of volume of the bed (V),activity of the biodegrader (A), concentration of oxygenate(s) ininfluent (C_(in)), and concentration of oxygenate(s) in the effluent toderive (B), the dry mass of the biodegrader needed to degrade theoxygenate(s), for example MTBE, in the water stream.

Biodegrader

Biodegraders suitable for use in the present invention are bacteriacapable of biodegradation of an oxygenate or a plurality of oxygenates.The term “oxygenate(s)” are oxygen containing hydrocarbons which includealkyl ethers and alkyl alcohols, particularly branched alkylethers/alcohols, and more particularly MTBE and TBA. The termbiodegrader includes, but is not limited to mixed bacterial cultures,isolated mixed bacterial cultures, pure (single cell) bacterialcultures, derivatives of mixed or pure bacterial cultures, and the like.Examples include the mixed cultures described in U.S. Pat. No.5,750,364, U.S. Pat. No. 5,811,010, and U.S. Pat. No. 5,902,734, t oSalanitro, assigned to Shell, and incorporated herein by reference inthe entirety. Also particularly well suited is the pure (single cell)bacterial culture described in copending U.S. patent application Ser.Nos. 09/292037, 09/438595, and 09/439905, assigned to Shell andincorporated by reference herein in the entirety.

Following is a brief description of the isolated mixed culture, havingthe identifying characteristics of BC-1, ATCC No. 202057, which isdescribed in detail in U.S. Pat. No. 5,750,364. BC-1 aerobicallydegrades MTBE, added to the culture at a concentration of 0.01 to 500ppm, to carbon dioxide, and also degrades tertiary butyl alcohol. BC-1also degrades other tertiary carbon-containing ether compounds. The BC-1mixed culture is prepared by adding a branched alkyl ether to biosludge(activated sludge), incubating for a period of time, adding mineralnutrient, and enriching the culture by adding a suitable amount ofbranched alkyl ether.

The pure culture described in copending U.S. patent application Ser.Nos. 09/439905, 09/292037, and 09/438595 belongs to the familyActinomycetes and the species Rhodococcus and can be isolated from BC-1or any other mixed culture, having the identifying characteristics ofbeing able to degrade aerobically MTBE added to the culture at aconcentration of 0.01 to 500 ppm, to carbon dioxide. One non-limitingexample of the preparation of a pure culture includes the preparation ofa mixed culture using the method described in U.S. Pat. No. 5,750,364.Then the pure culture is prepared by adding, for example, about 10 ml ofthe mixed culture to about 10 ml of sterile Difco Bushnell-Haas (MgSO₄,200 mg/L; CaCl₂, 20 mg/L; KH₂PO₄, 1000 mg/L; K₂HPO₄1000 mg/L; NH₄NO₃1000 mg/L; FeCl₃, 50 mg/L, pH 7.0) mineral medium (3.5 g/L; referred toas BH) in stoppered serum bottles containing 1-5 mg/L MTBE. At weeklyintervals, half of the culture volume (10 ml) is aseptically removed and10 ml fresh sterile BH medium added to the remaining 10 ml of culture.The dilution enrichment method is continued for at least 2-3 months at25° C. until a dilute suspension of bacteria degrading MTBE consistentlydegrade MTBE before each transfer interval. This dilution enrichmentculture is subsequently streaked onto sterile Petri plates containing BHminerals plus 1.5% Difco Agar as a solidifying agent. Plates wereincubated at 25° C. or 30° C. and observed for the appearance ofcolonies after 3-5 days. Approximately 20 colonies are picked withsterile needles and inoculated into 20 serum vials containing sterile BHmedium and 1-10 mg/L MTBE. These cultures are incubated at 25-30° C. andthe loss of MTBE from the headspace of serum vials is determined. Oneisolate, identified as SC-100, completely degraded MTBE without anysignificant appearance of intermediates such as t-butyl alcohol.

SC-100 also degrades other ether oxygenates besides MTBE, such as, forexample, TAME, ETBE, DIPE, and TBA. A BC-1 mixed bacterial culture in aconcentration of 0.3 g/L can degrade MTBE at 5, 8, 15, and 35 ppm in 2,3, 6, and 10 hours respectively. The pure bacterial culture SC-100, forexample, at a concentration of 2.4 g/L (glucose- grown) degrades MTBE at10, 20, 40, and 80 ppm in 18-24 hours. Large scale amounts, for example,hundreds of Kg of the enriched mixed cultures of this invention withhigh specific MTBE removal activity (10-30 mg/g/h) can be readilyobtained from Shell Global Solutions, Houston, Tex., U.S.A., for seedingGAC beds of any size.

As used herein, derivatives of mixed or pure bacterial cultures includeany compositions derived from said mixed or pure bacterial cultures.Examples of the compositions derived from the pure bacterial cultureinclude, but are not limited to, members of, fragments of the bacterialculture, membrane fragments of bacterial culture, enzymes extractedand/or isolated from the bacterial culture, lyophilized and/or driedculture, lyophilized and/or dried fragments of culture, lyophilizedand/or dried enzymes derived from said culture, bacterial culture and/orfragments thereof and/or enzymes derived therefrom bound to a carrierand/or binder and/or fixed bed, etc. Any method known to one skilled inart for making composition derived from a culture including but notlimited to extraction or fragmentation to obtain activeingredients/fragments thereof is within the scope of the presentinvention.

Method of Determining Amount of Biodegrader to be Employed

As mentioned, an important aspect of the present invention is the amountof bio- degrader or bacteria to use, and a critical element of theinvention is the method of seeding in order to prevent plugging of theGAC. The amount of biodegrader needed to treat a given amount of MTBEcan be determined by analysis of the relationship represented by:$B = \frac{\left( {0.1 - 10} \right)\quad {\left( {C_{in} - C_{out}} \right) \cdot F}}{A}$

More specifically,$B = \frac{\left( {0.5 - 5} \right)\quad {\left( {C_{in} - C_{out}} \right) \cdot F}}{A}$

Still more specifically,$B = \frac{\left( {0.8 - 2} \right)\quad {\left( {C_{in} - C_{out}} \right) \cdot F}}{A}$

Where

B=dry mass of biodegrader needed, (gm)

C_(in)=concentration of oxygenate(s) or MTBE in the influent, (mg/l)

C_(out)=desired concentration of oxygenate(s) or MTBE in the effluent(mg/l)

F=flow rate of water to be treated, l/hr

A=biodegrader activity in mg of compound degraded/hr/gm of biomass

V=volume of the empty carbon bed, Liters

A should be higher than 2, preferably higher than 8. The ratio of volumeto flow rate (V/F) should be greater than 0.05 h., preferably greaterthan 0.5 h and more preferably greater than 1 h.

Calculations of a suitable amount of biodegrader are based on dry weightof the degrader or bacteria culture.

Generally we have found that an amount of biodegrader anywhere from 100mg to 5000 mg can work, however a more suitable amount is from about 500mg to 2500 mg (dry basis) per Kg of granular activated carbon (drybasis) in the bed. A typical amount used to demonstrate the inventionwas 1000 mg (dry basis) of our mixed culture per Kg of granularactivated carbon (dry basis) in the bed. Significantly more than thiscan lead to plugging or channeling while less than this lengthens thestart-up period due to inadequate establishment of colonies of thedesired biodegrader.

As another embodiment of the present invention, the flow rate can bedetermined by the following:$F = \frac{A \cdot B}{\left( {0.1 - 10} \right)\quad \left( {C_{in} - C_{out}} \right)}$

As an illustrative example where the values are as follows:

A=biodegrader activity is assessed to be 5 mg/g/hr

B=dry mass of biodegrader needed is 181 gm

C_(in)=concentration of MTBE in the influent is 2 ppm

C_(out)=desired concentration of MTBE in the effluent is <10 ppb$\begin{matrix}{F = \frac{A \cdot B}{\left( {0.1 - 10} \right)\quad \left( {C_{in} - C_{out}} \right)}} \\{F = \frac{5\quad {mg}\text{/}L\text{/}{{hr} \cdot 181}\quad {gm}}{\left( {0.1 - 10} \right)\quad \left( {{{2\quad {ppm}} -} < {10\quad {ppb}}} \right)}} \\{F = {\left( {0.1 - 10} \right)\quad 454\quad l\text{/}{hr}}}\end{matrix}$

As another embodiment of the present invention the biodegrader activityin mg of compound degraded/hr/gm of biomass can be determined by thefollowing:$A = \frac{\left( {0.1 - 10} \right)\quad {\left( {C_{in} - C_{out}} \right) \cdot F}}{B}$

As an illustrative example where the values are as follows:

C_(in)=concentration of MTBE in the influent is 2 ppm

C_(out)=desired concentration of MTBE in the effluent <10 ppb

F=flow rate of water to be treated is 454 l/hr

B=dry mass of biodegrader needed is 181 gm $\begin{matrix}{A = \frac{\left( {0.1 - 10} \right)\quad {\left( {C_{in} - C_{out}} \right) \cdot F}}{B}} \\{A = \frac{{\left( {0.1 - 10} \right)\quad {\left( {{{2\quad {ppm}} -} < {10\quad {ppb}}} \right) \cdot 454}\quad l\text{/}{hr}}\quad}{181\quad {gm}}} \\{A = {\left( {0.1 - 10} \right) \times 5\quad {mg}\text{/}{gm}\text{/}{hr}}}\end{matrix}$

Inoculation Method and Apparatus

As mentioned a critical element of this invention is the method ofinoculation. In seeding the GAC bed, it is important that thebiodegrader be dispersed evenly in the carbon bed. Uneven distributionresults in plugging and bypassing of some parts of the bed.

FIG. 1 is a diagram of the GAC inoculation equipment. The size of theequipment can vary and may range from laboratory scale to commercialscale as will be apparent to those skilled in the art. The biomass 1 isheld in a circulation tank 2. The tank is connected to a pump 4 by line3. The pump is connected to the BioGAC reactor by a flexible hose orline 6. The flexible hose is connected to rigid tubing, or inoculation“wand”, 7 which is inserted into the BioGAC reactor 10 and into thecarbon bed 11. The last section, about six inches, of the end of therigid tubing is shown in the enlargement FIG. 1A. The end of the rigidtubing contains holes, represented by 9, through which the biomass exitsand enters the carbon bed 11. The end of the rigid tubing can be fittedwith a plug that can be opened or closed during loading operationsdepending on conditions. 19 represents a rigid plastic pipe open to theatmosphere and 17 represents a tee. Groundwater is fed into the BioGACreactor through the groundwater feed line 19.

Still referring to FIG. 1, in the method used for inoculating or loadingbiomass onto a BioGAC bed, the inlet 3 to the pump is connected to thecirculation tank which holds the biomass to be loaded. The biomass inthe tank is diluted with water, typically groundwater. The MTBE degradershould be diluted to prevent localized bed plugging. Suitable biomassconcentration after dilution is in the range of 100 mg/L to 5000 mg/L,with a preferred range being 500 mg/L to 3000 mg/L, and a concentrationafter dilution of less than 2000 mg/I working very satisfactorily.

The diluted biomass is pumped from the tank 2 through the flexibletubing 6 to the rigid tubing 7 and through the holes in the end of thetube 9 at a high velocity and enters the GAC bed. The high velocity offluid leaving the tubing causes the carbon bed in the immediate vicinityof the end of the rigid tubing to “fluidize”, which provides good localmixing and makes it easy to push the rigid tubing through the GAC bed.While the diluted biomass is being pumped through the tube, the tubeitself is continually moved around the GAC bed to give an evendistribution of the biomass.

As the biomass is being pumped into the GAC bed, the water level willrise somewhat in the GAC vessel giving rise to a liquid head whichforces water out the bottom of the GAC vessel 15. The outlet of the GACvessel 15 is connected to a vertical piece of rigid pipe 19 with a tee17 just slightly above the level of the top of the GAC bed. The heightof this tee will determine the liquid height above the GAC bed. Thestraight-through portion of the tee is connected to a short piece ofvertical pipe open to the atmosphere 16 which serves as a vacuumbreaker. The middle part of the tee is connected to a flexible hose 18which goes to the tank containing the diluted biomass. In this way, thewater carrying the biomass onto the bed is returned to the tank whilethe biomass is retained on the bed through filtration by the carbonparticles.

As the seeding of the bed takes place, the biomass content in the tankwill gradually decrease and the water in the tank will become clearer.Depending upon the total amount of biomass to be loaded, several cyclesmay be required, each cycle comprising placing a fixed amount of biomassin the tank, diluting it by adding water to the tank, and loading thebiomass onto the GAC bed as described above until there is not muchbiomass left in the tank, indicated by the increasing clarity of thewater in the tank.

The inoculation process is finished when the biomass or biodegraderconcentration in the feed tank is reduced to clean water levels. Thismay take up to 8 hours, more often up to 4 hours.

The amount of biodegrader to load must be enough to develop abiodegrading culture on the carbon within a short time period, say lessthan 90 days, preferably 30 to 60 days, however the amount should not beso much that it causes plugging of the bed and/or channeling. Pluggingof the bed prevents fluid flow through the bed, and necessitates the GACbe backwashed or the carbon replaced, removing the biodegrader from thesystem and losing time in either case. Where channeling occurs in thebed, fluid can still flow, but the actual detention time of the fluid inthe bed is much less than the design the invention provides for,resulting in poor, if any, MTBE removal.

The amount of MTBE biodegraders that a GAC bed can handle is partlydependent on the head loss characteristics of the interaction betweenthe carbon particles and the biodegrader particles added and on theallowable pressure within the GAC vessel.

The rigid tubing 7, or inoculation “wand”, in FIG. 1 is an instrumentfor inoculating the biodegrader in the GAC that is a key part of thepresent invention. As discussed above poor dispersion of the biodegraderwhen seeding the GAC bed results in poor removal of MTBE. Theinoculation instrument disclosed herein is generally a rigid tube,connected to the flexible hose bringing biomass from the storage tank byway of the pump, said rigid tubing having a diameter appropriate to thescale of the other equipment, generally in the range of ½ in. to 2 in.,preferably about ½ in. to 1 inch, having a series of small holes drilledin the last section of the bottom edge, generally the last 5 to 10inches of the end inserted in the GAC.(See FIG. 1A)

The rigid tubing can be made of any rigid material. Suitable metalswould include copper and steel. Rigid plastic tubing is also acceptable.Particularly suitable is stainless steel.

In one nonlimiting embodiment of the invention, using equipment asgenerally described in FIG. 1 and 1A, the rigid tubular instrument forloading biomass was a piece of rigid stainless steel tubing about ¾ in.diameter connected on one end via flexible tubing to the outlet of apump and having a series of small holes drilled in the other end. Aboutfour to six ¼ in. holes in the last 6 inches of steel tubingaccomplished the desired objectives. The inlet to the pump is connectedto a small circulation tank (˜30-50 gal) which holds the biomass to beloaded onto the GAC bed. The biomass in the tank is diluted with water(typically site groundwater) so the biomass (TSS) concentration does notexceed 2000 mg/L. The diluted biomass is pumped from the tank andthrough the rigid tubing at a rate of about 5 to 15 gpm. The end of therigid tube with the holes is placed in the GAC bed through the openingat the top of the GAC vessel. The diluted biomass liquid exits the rigidtubing through the holes in the end of the tube at a high velocity andenters the GAC bed. The high velocity of fluid leaving the tubing causesthe carbon bed in the immediate vicinity of the end of the rigid tubingto “fluidize”, which provides good localized mixing and makes it easy topush the rigid tubing through the GAC bed. While the diluted biomass isbeing pumped through the tube, the tube itself is continually movedaround the GAC bed to give even distribution of the biomass.

In an alternative embodiment, the GAC bed can be fluidized through thebackwash of the bed. The degree of bed expansion required depends on theMTBE degrader particle size distribution, with small discrete particlesrequiring less bed expansion. Generally the required bed expansion willprobably be in the range of 2% to 30%, but more often in the range of 5%to 15%.

Nutrients

As with any aerobic biotreatment system, the biodegrader on the GAC bedneeds oxygen to survive and degrade MTBE. There is sometimes someresidual oxygen in the recovered groundwater, depending on the type ofrecovery well and pump, but the dissolved oxygen level is ofteninconsistent and not always high enough to meet the biodegraderrequirements.

In the present invention it has been found preferable to provide anyadditional oxygen in the form of hydrogen peroxide rather than as air oroxygen. If additional oxygen is needed, it is provided by pumping asolution of hydrogen peroxide into the groundwater feed line to the GACbed. The amount of hydrogen peroxide required is determined from theamount of biodegradable oxygen demand in the water. A precision meteringpump (typically a piston or diaphragm pump) is used to pump the hydrogenperoxide.

The hydrogen peroxide is typically used diluted to a concentration inthe range of 5% to 30%, preferably about 15% to 25%, most preferablyabout 20%.

A minimum amount of hydrogen peroxide solution is from about 6 to 9weight units of H₂O₂ per weight units of MTBE or other oxygenate. Apreferred amount is about 10 weight units.

For groundwater containing only MTBE and TBA, the concentration ofbiodegradable oxygen demand is just the concentration of MTBE times 2.73plus the concentration of TBA times 2.59. The biodegradable oxygendemand is then multiplied by the recovered groundwater flow rate todetermine the required oxygen concentration. The residual oxygendissolved concentration is subtracted from this number and the resultingnumber is then divided by 0.47 to determine the required mass flow rateof hydrogen peroxide. Using the density and concentration (typically20%) of the hydrogen peroxide solution, the required volumetric flowrate of the hydrogen peroxide solution can then be calculated.

In addition to oxygen the biodegrader requires nutrients to achieveeffective biodegradation. Major nutrients are nitrogen- andphosphorus-containing compounds and they must be provided to thebiodegrader on the GAC bed to achieve effective survival of the cultureand biodegradation of MTBE. Compounds providing major nutrients include,but are not limited to, NaNO₃, NH₄Cl, and KH₂PO₄. The nutrients used todemonstrate the invention are sodium nitrate and sodium phosphatemonobasic. A suitable amount of nitrate-N or ammonia-N nitrogen sourceis about 0.03 to 0.14 wt units nitrate or ammonia-N to wt units of MTBE,preferably about 0.05 to 0.10 and, in most cases close to 0.07 wt unitsof nitrate-N or ammonia-N to wt unit of MTBE. A suitable amount ofphosphorus or phosphate containing compound is about 0.005 to 0.03 wtunits phosphate-P to wt units of MTBE, preferably about 0.01 to 0.02,and in most cases close to about 0.015 wt units of phosphorus orphosphate to wt units of MTBE.

In a nonlimiting illustrative example a concentrated solution containingsodium nitrate (˜20 g/L) and sodium phosphate monobasic (˜2.5 g/L) ispumped into the groundwater feed line to the GAC bed. This can be pumpedin separately from the hydrogen peroxide, or a combined solutioncontaining the hydrogen peroxide along with the nutrient compounds canbe utilized, thus reducing the requirement from two to one meteringpump. If the nutrients are combined with the hydrogen peroxide, theconcentration of hydrogen peroxide and nutrients should be adjusted togive a weight ratio of hydrogen peroxide to N to P of 10 to 0.07 to0.015.

Environmental temperature and pH do have an effect on the biodegrader orbacteria's rate of organic degradation. Although the range is notcritical, a temperature range between about 10 and 30° C., preferablyabout 19-25° C., is most conducive to the degradation process. Withrespect to pH, it is preferred that the pH be in the range of 6.0 to9.0, preferably 6.5 to 8.5, and most preferably between 7.0 and 8.0.

The following examples will serve to illustrate the invention disclosedherein. The examples are intended only as a means of illustration andshould not be construed as limiting the scope of the invention in anyway. Those skilled in the art will recognize many variations that may bemade without departing from the spirit of the disclosed invention.

EXAMPLE 1

Example 1 describes the start-up, operation and results of a 55-gallonactivated carbon drum pilot plant unit. Loading of the 55-gallon carbondrum was accomplished by injecting the microorganisms into the carbondrum through a 4-foot, ¾ inch (OD) SS tube wand. The lower 6 inches ofthe wand was perforated with ˜{fraction (3/16)} inch holes around thecircumference. A plug was fitted to the end of the tubing that could beopened or closed depending on the conditions during loading operations.The drum lid was removed and the bacteria were pumped through the wandat about 6-8 gpm. Concentration of the bacteria injected was in generalbetween 1500-2000 mg/L TSS. Higher or lower microorganism TSSconcentrations may be used depending on conditions of the carbonenvironment. The wand is moved up/down and around the circumference ofthe carbon bed to ensure maximum dispersion of the organisms throughoutthe bed. Periodically the resultant overflow of liquid is recycled tothe inoculation feed tank until the overflow is clear. After the desiredloading (mg TSS microorganism/Kg dry carbon) is achieved (generally 2500mg/Kg) with a clear effluent overflow, the inoculation process iscomplete. The drum lid is then secured and the operation of the unitbegins.

The drum is fitted with the necessary piping to facilitate down-flow ofpumped organic/nutrient/oxygen enriched feed solution through the carbonbed. The drum is also fitted with a gauge to monitor pressure and an airvent to relieve any build-up of process gases. The feed is comprised ofabout 2 PPM MTBE and 0.5 PPM TBA, a nitrogen/phosphorus salt solutionand a hydrogen peroxide solution that is pre-mixed together in aseparate feed tank before being introduced to the carbon bed.

Once the carbon drum has been inoculated, the feed is introduced to theunit at 2 gpm. At this size carbon drum and feed concentration and flow,the following was monitored and adjusted to maintain the followingconditions:

a. Dissolved oxygen concentration exiting the unit was greater than orequal to ˜1-2 PPM by adjusting the hydrogen peroxide concentration inthe feed.

b. Nitrogen and phosphorus concentrations were maintained at ˜1.5 and0.3 mg/L, respectively.

c. It should be noted that the environmental temperature and pH have aneffect on the microorganism's rate of organic degradation. Temperatureand pH were not regulated during these pilot plant operations; however,the feed solution (primarily industrial WTC plant water) was about19-25° C. and the pH remained between 7.0 and 8.0 during theseexperiments.

On day 1, Unit S2A was inoculated with 216 grams (dry wt.) of mixedculture MTBE degrading bacteria. Since that time until 160 days later,no changes have been made to the unit feed and no additional bacteriahave been added.

Once the mixed culture was in place for approximately 100 days fromaddition at day 1, we have consistently demonstrated the reduction ofinfluent MTBE/TBA concentrations from 2 PPM MTBE and 0.5 PPM TBA to 1PPB and 5 PPB, respectively. The unit pressure has risen from about 1 to6 psig.

FIG. 2A is a graph of the influent and effluent MTBE, showing theperformance of the BioGAC reactor. FIG. 2B shows influent and effluentTBA.

Within 30 days the effluent MTBE decreased to 1 ppm and within 100 daysto <10 ppb.

EXAMPLE 2

Example 2 is one illustrative but not restrictive example of using theformula of the present invention to determine the amount of biomass touse in inoculating the GAC. The equipment for this example would be asdescribed in FIG. 1. The C_(in) of influent MTBE was 2 ppm. DesiredC_(out) of effluent MTBE was <10 ppb. The flow rate of the groundwaterto be treated was F=4541 l/hr.

The degrader activity (A) of the biomass to be employed was assessed tobe about 5 mg/g/hr. The amount of degrader needed was determined usingthe formula: $\begin{matrix}{B = \frac{\left( {0.1 - 10} \right)\quad {\left( {C_{in} - C_{out}} \right) \cdot F}}{A}} \\{B = \frac{\left( {0.1 - 10} \right)\quad {\left( {{{2\quad {ppm}} -} < {10\quad {ppb}}} \right) \cdot 454}\quad l\text{/}{hr}}{5\quad {mg}\text{/}g\text{/}{hr}}} \\{B = {\left( {0.1 - 10} \right) \times 181\quad {gm}\quad \left( {{dry}\quad {mass}\quad {of}\quad {degrader}{\quad \quad}{needed}} \right)}}\end{matrix}$

We claim:
 1. A method of treating groundwater, or other water streamcontaminated with an oxygenate to degrade said oxygenate whichcomprises: a) Inoculating a biodegrader capable of degrading saidoxygenate on an activated carbon bed through a rigid tubular instrumenthaving a plurality of holes around the circumference of the end used forinoculation of the carbon bed; and b) Flowing said groundwater, or otherwater stream contaminated with said oxygenate through a structure havinga top, bottom and sides and a predetermined volume containing said bedof activated carbon having said biodegrader inoculated thereon.
 2. Themethod according to claim 1 further comprising said structure has aninlet port through which an influent liquid stream containing saidoxygenate enters said structure; and an outlet port through which aneffluent liquid stream containing degraded oxygenate exits.
 3. Themethod according to claim 2 further comprising: Flowing said groundwateror other water stream contaminated with oxygenate(s) at a flow rate (F)through said structure having a predetermined volume (V) containing abed of activated carbon, wherein the concentration of contaminant ininfluent is represented by (C_(in)); the concentration of said oxygenatein effluent is represented by (C_(out)); the biodegrader has a dry mass(B), and activity (A), and wherein A, B, F, C_(in) and C_(out) have thefollowing relationship:$B = \frac{\left( {0.1 - 10} \right)\quad {\left( {C_{in} - C_{out}} \right) \cdot F}}{A}$

 Where B=dry mass of biodegrader needed to degrade oxygenate(s), (gm)C_(in)=concentration of oxygenate(s) in the influent (mg/l)C_(out)=desired concentration of oxygenate(s) in the effluent (mg/l)F=flow rate of water to be treated, L/hr A=biodegrader activity in mg ofcompound degraded/hr/gm of biomass.
 4. The method according to claim 3further comprising means for controlling the flow of influent.
 5. Themethod according to claim 4 further comprising the ratio of volume toflow rate (V/F) is greater than 0.05 h.
 6. The method according to claim5 wherein the ratio of volume to flow rate (V/F) is greater than 1 h. 7.The method according to claim 2 further comprising said outlet of saidstructure is connected to a vertical piece of rigid pipe with a tee justslightly above the level of the top of the granular activated carbonbed.
 8. The method according to claim 7 further comprising the straightthrough portion of the tee is connected to a short piece of verticalpipe open to the atmosphere that serves as a vacuum breaker.
 9. Themethod according to claim 7 further comprising the middle part of thetee is connected to a flexible hose, which goes to a holding tankcontaining biodegrader.
 10. The method according to claim 9 furthercomprising the water carrying the biodegrader onto the GAC bed isreturned to the holding tank while the biodegrader is retained on thebed through filtration by carbon particles in the bed.
 11. The methodaccording to claim 2 further comprising the biodegrader requires anoxygen source.
 12. The method according to claim 11 wherein the amountof oxygen required is determined from the amount of biodegradable oxygendemand in the water.
 13. The method of claim 12 wherein the watercontains only MTBE and TBA and the concentration of biodegradable oxygendemand is =[MTBE]×2.73+[TBA]×2.59.
 14. The method of claim 13 furthercomprising the biodegradable oxygen demand is multiplied by a recoveredgroundwater flow rate to determine the required mass of oxygen.
 15. Themethod according to claim 11 further comprising means for supplyingoxygen as hydrogen peroxide.
 16. The method according to claim 15further comprising the oxygenate(s) comprises predominantly MTBE. 17.The method according to claim 16 further comprising the amount ofhydrogen peroxide added is greater than 6 wt units of hydrogen peroxideper weight unit of MTBE.
 18. The method according to claim 17 furthercomprising the amount of hydrogen peroxide added is greater than 9 wtunits of hydrogen peroxide per weight unit of MTBE.
 19. The methodaccording to claim 15 further comprising the hydrogen peroxide is addedin a concentration of about 10% to 30%.
 20. The method according toclaim 19 wherein the hydrogen peroxide is added in a concentration ofabout 15% to 25%.
 21. The method of claim 15 further comprising therequired mass flow rate of a hydrogen peroxide is determined bysubtracting the residual oxygen dissolved concentration from therequired mass of oxygen and dividing by 0.47.
 22. The method accordingto claim 2 further comprising means for supplying suitable nutrients tothe biodegrader bacteria.
 23. The method of claim 22 wherein thenutrient is at least one nutrient selected from the group consisting ofelemental nitrogen or compounds thereof and elemental phosphorous orcompounds thereof.
 24. The method of claim 23 wherein the nutrient isone or more nutrients selected from the group consisting of NaNO₃,NH₄Cl, and KH₂PO₄.
 25. The method of claim 24 wherein the nutrient isselected from sodium nitrate and sodium phosphate monobasic.
 26. Themethod according to claim 22 further comprising the means for supplyingnutrients is combined with a means for supplying oxygen.
 27. The methodaccording to claim 22 wherein the means for supplying nutrients isseparate from a means for supplying oxygen.
 28. The method according toclaim 22 further comprising the amount of nutrient required isdetermined from the amount of biodegradable oxygen demand in the water.29. The method according to claim 28 wherein the water contains onlyoxygenate(s) MTBE and TBA and the concentration of biodegradable oxygendemand is =[MTBE]×2.73+[TBA]×2.59.
 30. The method of claim 29 furthercomprising the biodegradable oxygen demand is multiplied by a recoveredgroundwater flow rate to determine the required mass of oxygen.
 31. Themethod of claim 20 wherein said nutrients comprise nitrogen andphosphate and further comprising the required mass flow rate of nutrientis determined by multiplying the required mass of oxygen by 0.025 for Nand 0.005 for P.
 32. The method according to claim 1 further comprisingduring inoculation said structure is in communication with a holdingtank where the biodegrader is stored.
 33. The method according to claim32 wherein said communication between the holding tank and structurecontaining the activated carbon bed comprises a flexible tube exitingsaid holding tank which connects to said rigid tubular instrument thatenters the carbon bed for inoculation.
 34. The method according to claim33 further comprising the rigid tubular instrument is a size anddiameter appropriate for the dimensions of the structure containing thecarbon bed and of the holding tank.
 35. The method according to claim 34wherein the rigid tubular instrument is a rigid plastic.
 36. The methodaccording to claim 34 wherein said rigid tubular instrument is a metal.37. The method according to claim 36 wherein the rigid tubularinstrument is stainless steel.
 38. The method according to claim 34wherein said rigid tubular instrument has an overall diameter of from ½in. to 2 in.
 39. The method according to claim 34 wherein said rigidtubular instrument is about 1 ft. to 6 ft. in length, from theconnection to said flexible tubing to the end having the holes.
 40. Themethod according to claim 34 further comprising the rigid tubularinstrument is stainless steel, about 4 ft. long with an overall diameterof about ¾ in., and having about 4 to 6 holes of a diameter of about{fraction (3/16)} to ¼ in. drilled in about the last six inches.
 41. Themethod according to claim 33 further comprising there is a pump betweensaid holding tank and flexible tube and the biodegrader is pumpedthrough the flexible tubing and rigid tubular instrument and throughholes in the end of the rigid tubular instrument.
 42. The methodaccording to claim 41 further comprising said biodegrader is dilutedwith liquid selected from groundwater or other source of water.
 43. Themethod according to claim 42 wherein the biodegrader concentration afterdilution is in the range of 500 mg/L to 3000 mg/L.
 44. The methodaccording to claim 43 wherein the biodegrader concentration afterdilution is less than 2000 mg/l.
 45. The method according to claim 41wherein the biodegrader is pumped at a rate of about 2 to 20 gpm. 46.The method according to claim 45 wherein the biodegrader is pumped at arate of about 5 to 15 gpm.
 47. The method according to claim 41 furthercomprising the biodegrader exits the holes at high velocity, and thehigh velocity of fluid leaving the tubing causes “fluidization” of thecarbon bed in the immediate vicinity of the end of the rigid tubing,which provides good local mixing and makes it easy to push the rigidtubing through the GAC bed.
 48. The method according to claim 47 furthercomprising while the biodegrader is being pumped through the tubularinstrument, the tubular instrument itself is continually moved around toprovide even distribution of the biodegrader.
 49. The method accordingto claim 47 further comprising fluidizing the GAC bed through backwashpump action.
 50. The method according to claim 1 wherein said rigidtubular instrument has holes in the circumference in the last 4 to 10inches.
 51. The method according to claim 1 wherein the holes in thecircumference of the rigid tubular instrument are ⅛ in. to ½ in. indiameter.
 52. The method according to claim 1 wherein the structure witha predetermined volume is a fixed bed reactor.
 53. The method accordingto claim 1 wherein the oxygenate(s) is any substance that adds oxygen toa hydrocarbon.
 54. The method according to claim 53 wherein theoxygenate(s) is selected from ethers, alkyl ethers, and alkyl alcohols.55. The method according to claim 54 wherein the oxygenate is selectedfrom branched alkyl ethers and branched alkyl alcohols.
 56. The methodaccording to claim 55 wherein the oxygenate is a tertiary carbonatom-containing alkyl ether or a tertiary carbon atom-containingalcohol.
 57. The method according to claim 56 wherein the oxygenate(s)is selected from MTBE and TBA, and an ether, alkyl ether, branched alkylether.
 58. The method according to claim 57 wherein said oxygenate(s)comprises methyl tertiary butyl ether (MTBE) and tertiary butyl alcohol(TBA), and optionally one or more compounds selected from the groupconsisting of diethyl ether (DEE), dimethyl ether (DME), methyl ethylether (MEE), methyl n-propyl ether (MPE), ethyl n-propyl ether, methylisopropyl ether, ethyl isopropyl ether, di-t-butyl ether, di-isopropylether (DIPE), di-isobutyl ether, isopropyl isobutyl ether, ethyl t-butylether (ETBE), t-amyl ethyl ether, t-amyl propyl ether, t-amyl isobutylether and methyl-t-amyl ether.
 59. The method according to claim 57characterized by improved biodegradation of alkyl ethers and MTBE, thebiodegradation of TBA, and reduced frequency of the need to change theactivated carbon bed.
 60. The method according to claim 57 wherein thebiodegrader in (a) is selected from the group consisting of BC-1, ATCCno. 202057, and SC-100.
 61. The method according to claim 60 wherein theoxygenate is degraded to carbon dioxide and water.
 62. The methodaccording to claim 1 wherein the size of the granular activated carbonparticles is larger than 50 mesh (U.S. Standard sieve).
 63. The methodaccording to claim 1 wherein the biodegrader in (a) is selected from thegroup consisting of mixed bacterial cultures and derivatives thereofcapable of biodegradation of ethers and pure bacterial cultures andderivatives thereof capable of biodegradation of ethers.
 64. The methodof claim 63 wherein compositions derived from bacterial cultures areselected from fragments of the bacterial culture, membrane fragments ofbacterial culture, enzymes extracted and/or isolated from the bacterialculture, lyophilized and/or dried culture, lyophilized and/or driedfragments of culture, lyophilized and/or dried enzymes derived from saidculture, bacterial culture and/or fragments thereof and/or enzymesderived therefrom bound to a carrier and/or binder and/or fixed bed. 65.The method of claim 63 wherein compositions derived from bacterialculture includes compositions derived by any method known to one skilledin the art for making a composition derived from a culture.
 66. Themethod according to claim 63 wherein the biodegrader in (a) is selectedfrom the group consisting of BC-1, ATCC no. 202057, and SC-100.
 67. Amethod of treating groundwater, or other water streams contaminated withat least one oxygenate(s) selected from tertiary alkyl ether(s) andtertiary alkyl alcohol(s), characterized by improved biodegradation oftertiary alkyl ethers and tertiary alkyl alcohols and MTBE, thebiodegradation of TBA, and reduced frequency of the need to change thecarbon bed which comprises: a) Inoculating a biodegrader selected fromthe group consisting of BC-1, ATCC no. 202057, and SC-100, andderivatives thereof, capable of degrading said oxygenate(s) to carbondioxide and water, onto a granular activated carbon bed (GAC) through arigid tubular instrument having a plurality of holes around thecircumference of the end used for inoculation of the carbon bed; and b)Flowing said groundwater, or other water stream contaminated with saidoxygenate(s) through a structure having a top, bottom and sides and apredetermined volume containing said bed of activated carbon having saidbiodegrader inoculated thereon.
 68. The method according to claim 67wherein the oxygenate(s) is at least one selected from TAME, ETBE, DIPE,MTBE and TBA.
 69. An apparatus for the biodegradation of groundwatercontaminated with oxygenate(s) which comprises: a) At least onestructure having top, bottom and side walls of predetermined volume (V)containing therein granular activated carbon inoculated with abiodegrader; b) An inlet port in said structure through which aninfluent liquid stream containing said oxygenate(s) enters saidstructure; and c) An outlet port in said structure through which aneffluent liquid stream containing degraded oxygenate(s) exits; and d)Wherein said structure is in communication with a holding tank, wheresaid biodegrader is stored for inoculation, by a flexible tube thatbrings biodegrader from the storage tank to the structure containing thecarbon bed, and wherein said flexible tube is connected to a rigidtubular instrument having a plurality of holes in the circumference ofthe end.
 70. The apparatus of claim 69 wherein the reactor comprises adrum reactor.
 71. The apparatus of claim 69 wherein the biodegrader in(a) is selected from the group consisting of mixed bacterial culturesand derivatives thereof capable of biodegradation of ethers and purebacterial cultures and derivatives thereof capable of biodegradation ofethers.
 72. The apparatus of claim 71 wherein compositions derived frombacterial cultures are selected from fragments of the bacterial culture,membrane fragments of bacterial culture, enzymes extracted and/orisolated from the bacterial culture, lyophilized and/or dried culture,lyophilized and/or dried fragments of culture, lyophilized and/or driedenzymes derived from said culture, bacterial culture and/or fragmentsthereof and/or enzymes derived therefrom bound to a carrier and/orbinder and/or fixed bed.
 73. The apparatus of claim 71 wherein thebiodegrader is selected from the group consisting of BC-1, ATCC no.202057, and SC-100, and derivatives thereof.
 74. The apparatus of claim69 further comprising a pump to control flow between the holding tankand structure containing the inoculated GAC.
 75. The apparatus of claim69 further comprising the rigid tubular instrument is rigid plastic. 76.The apparatus of claim 69 further comprising said rigid tubularinstrument is a metal.
 77. The apparatus of claim 76 wherein the rigidtubular instrument is stainless steel.
 78. The apparatus of claim 69further comprising said rigid tubular instrument has holes in thecircumference of the end that contacts the GAC.
 79. The apparatus ofclaim 69 further comprising the dimensions of the rigid tubularinstrument are appropriate to the size of the structure containing thecarbon bed.
 80. The apparatus of claim 79 wherein said rigid tubularinstrument has a overall diameter of from ½ in to 2 in.
 81. Theapparatus of claim 70 wherein said rigid tubular instrument is about 2to 10 ft. in length from the connection to said flexible tubing to theend with the holes.
 82. The apparatus of claim 79 wherein saidinstrument has holes in the circumference in the last 2 in. to 1 ft. 83.The apparatus of claim 82 wherein the holes are ⅛ in to ½ in. indiameter.
 84. The apparatus of claim 79 further comprising the rigidtubular instrument is stainless steel, about 4 ft. long with an overalldiameter of about ¾ in., and having about 4 to 6 holes of a diameter ofabout ⅛ to ¾ in. drilled in about the last six inches.
 85. The apparatusof claim 69 further comprising a back wash pump for fluidizing the GACbed.
 86. The apparatus of claim 69 further comprising said outlet ofsaid structure is connected to a vertical piece of rigid pipe with a teejust slightly above the level of the top of the GAC bed, wherein the teeis characterized by a straight through portion and a middle portion. 87.The apparatus of claim 86 further comprising the straight throughportion of the tee is connected to a short piece of vertical pipe opento the atmosphere that serves as a vacuum breaker.
 88. The apparatus ofclaim 86 further comprising the middle part of the tee is connected to aflexible hose, which goes to the tank containing biodegrader.
 89. Theapparatus of claim 88 which allows water carrying the biodegrader ontothe GAC bed to return to the holding tank while the biodegrader isretained on the bed through filtration by carbon particles in the bed.90. The apparatus of claim 69 further comprising a means for adding anoxygen source and nutrients.
 91. The apparatus of claim 69 furthercomprising a means for monitoring pressure and a means for releasingpressure.